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Beating the poppy seed defense

During my PhD, one of the research projects I was involved in was a relapse prevention study testing individuals who had previously been addicted to alcohol, cocaine or heroin, but were no longer using any drugs.

One participant who took part in the study — I’ll call him Dave — was a young guy who was dependent on alcohol, but swore up and down he had never abused any drugs. Dave was three weeks into the study and doing well, staying abstinent and remaining cheerful and cooperative throughout the sessions. However, one morning when Dave came in and went through his usual drug screen, he tested positive for heroin, something he claimed (and I believed) he had never taken.

Instead, Dave maintained he had eaten a poppy seed bagel for lunch the day before, which would explain the positive test.

Opiates — like heroin, morphine or opium — are all derived from the poppy seed plant, and it’s not uncommon for poppy seeds to give a false-positive result for opiates on a drug screen. However, it’s also not uncommon for people to falsely plead the poppy seed defense, and there is no way of confirming what form of morphine (heroin or poppy seed) is actually causing the positive screen. Until now.

Researchers from King’s College London have discovered a metabolite of heroin that only exists in the synthetic form of the drug and can be reliably tested for using a urine screen. This means that instead of screening for all types of opiates, doctors and researchers can now test for only the presence of heroin in the body.

Notably, the test would also not come back positive for any prescription painkillers, which is simultaneously an advantage and a disadvantage of the new screen. For those who are legitimately prescribed the medications, there would be no more concerns over having a suspicious positive result. However, the tests would also not be able to identify the more than 12 million Americans who are using these drugs without a prescription. This is especially problematic as prescription painkillers have quickly surpassed all other types of drugs as the most common form of overdose, totaling more deaths in 2010 than cocaine and heroin combined, and prescription painkiller overdose has now become the leading cause of death by injury in the U.S.

The new test is still under investigation and isn’t perfectly refined (only 16 of the 22 known current heroin users tested positive for the metabolite in the study — meaning it has a detection rate of only about 75%), but it is a promising new avenue for researchers and medical screeners to more accurately identify the presence of heroin.

As for Dave, he successfully completed the study without any other events, and he never ate another poppy seed before a session again.